Despite marked health disparities among South Asians internationally compared to the U.S. population, little is known about the health status of South Asians residing in the U.S. Unfortunately, there is a paucity of research on tobacco use behaviors in South Asians. Moreover, tobacco consumption is characterized by a large proportion of indigenous tobacco products, such as bidis, which are small brown hand-rolled cigarettes, and gutkha and paan masala, types of chew tobacco. These popular South Asian tobacco products are also readily available in ethnic enclaves in the U.S. In addition, South Asians are the second largest Asian group in the U.S. and among the fastest growing immigrant groups. Existing studies of tobacco use in South Asians in the U.S. are limited as they tend to be geographically restricted or focused only on cigarette smoking. However, studies conducted in the U.K. suggest that immigrant South Asians may have high rates of tobacco use and may continue use of their native tobacco products. This exploratory research proposal describes a plan to explore measurement issues in tobacco use surveillance of South Asians in the U.S. Accordingly, we will: 1) conduct focus groups to understand tobacco use among South Asians in the U.S., 2) develop and refine a survey instrument, which will undergo cognitive testing, to assess the prevalence of products used by South Asians, 3) implement a population-based split sample randomized survey to compare standard tobacco use measures and new questions developed to measure South Asian-specific tobacco products, and 4) explore the feasibility of a respondent driven sampling (RDS) approach to reach South Asians. Thus, the significance of this proposed research is its potential to improve tobacco surveillance methodologies and generate a better understanding of indigenous tobacco use among South Asian immigrants which is vital to informing and directing tobacco control efforts. PUBLIC HEALTH RELEVANCE: The purpose of this research project is to explore measurement issues in tobacco use surveillance of South Asians in the U.S. Thus, the significance of this proposed research is its potential to improve tobacco surveillance methodologies and generate a better understanding of indigenous tobacco use among South Asians which is vital to informing and directing tobacco control efforts.